The present invention relates to a cartridge for conducting diagnostic assays. The cartridge consists of an assembly of components that are easily assembled. The cartridge provides means for receiving a patient sample, precisely controlling fluid introduction, onboard storage of assay fluid and conducting different assay protocols and detection of a plurality of analytes. Methods of use for the cartridge are described. The disclosed invention is suitable for point of care environments or any place where rapid, ultrasensitive testing is required.